1. Field of the Invention
The invention relates to an electronics enclosure, and in particular, to a highly configurable rackmount chassis.
2. Related Art
Large electronic installations are often implemented using rackmount architecture to provide maximum space efficiency and large-scale modularity. Rackmount systems typically follow the Electronics Industry Alliance (EIA) standard EIA-310-D that specifies an overall rackmount system width of 19 inches. Rackmount components must therefore be designed to fit within the specified system limits.
FIG. 1 shows an exemplary rackmount system 100 that includes a rack 110 populated by rackmount components 120. Rack 110 is simply a metal framework that defines an installation space for rackmount components 120. Rackmount components 120 (e.g., servers, routers, switches, and other electronic devices) are installed into rack 110, thereby providing a modular, standardized electronics system installation.
Each rackmount component 120 is a self-contained unit for providing a desired functionality. Typically, a rackmount component will be formed from a rackmount chassis that houses one or more “blades” (i.e., processors, memory, and/or other elements mounted on a circuit board). For example, a rackmount router may include multiple Ethernet blades that route network traffic to and from a larger bandwidth trunk. The overall capabilities of a rackmount component therefore depend on the number and type of blades installed in that rackmount component. Accordingly, those capabilities are in large part determined by the blade-mounting capacity of the rackmount chassis of the rackmount component.
FIG. 2A shows an isometric diagram of a conventional rackmount chassis 250. Rackmount chassis 250 includes an enclosure top 222T, an enclosure bottom 222B, and enclosure sides 222L and 222R that form a box-like enclosure. Side supports 223L and 223R are mounted within this box-like enclosure between enclosure top 222T and enclosure bottom 222B, and adjacent to enclosure side 222L and 222R, respectively. A center support 223C is mounted between enclosure top 222T and enclosure bottom 222B, midway between side support 223L and 223R.
To provide installation locations for blades within rackmount chassis 250, side supports 223L and 223R and center support 223C include multiple blade support slots 223B. Each blade support slot 223B in side supports 223L and 223R is positioned at the same level as a corresponding blade support slot 223B in center support 223C. Each of these pairs of blade support slots allows a blade to be installed into rackmount chassis 250.
For example, FIG. 2B shows an isometric diagram of a conventional rackmount component 220. Rackmount component 220 includes multiple blades 225 installed into rackmount chassis 250. The edges of each blade 225 slide in to one blade support slot 223B on one of side supports 223L and 223R, and the corresponding blade support slot 223B on center support 223C. In this manner, rackmount chassis 250 is populated with blades 225 to form a functional rackmount component 220.
Note that due to historical conventions, the side edge to side edge distance of a rackmount blade (i.e., the distance between the mounting edges of the blade, which are generally perpendicular to the electrical contact edge of the blade) is referred to as the “height” of the blade, even though the dimension is parallel to the width of the rackmount chassis. Thus, blades such as blades 225, which span roughly half the total width of rackmount component 220, are sometimes referred to as “half height” blades. Due to the construction of rackmount chassis 250 (i.e., a fixed center support 223C that runs between enclosure top 222T and enclosure bottom 222B), blades 225 must all exhibit the same height H. Therefore, replacing any of blades 225 with a larger or smaller blade is typically infeasible.
For example, blades 225 could all be fast Ethernet (i.e., 100 Mbps) network interface cards. Should increased network traffic handling capabilities be desired for rackmount component 220, it would be desirable to replace some or all of blades 225 with higher bandwidth gigabit Ethernet (i.e., 1 Gbps or 10 Gbps) or fiber optic network interface cards (blades). However, next generation technology is typically larger than existing generation technology. For example, if current fast Ethernet blades exhibit a half height form factor, next generation gigabit Ethernet blades may exhibit a full height form factor (i.e., a height that spans roughly the full width of the rackmount chassis). This blade size disparity would then preclude installation of the next generation technology into an existing rackmount component.
Consequently, to achieve the higher bandwidth benefits of the new blades, rackmount component 220 would be required to be uninstalled from its rack and be replaced with a different rackmount component having a rackmount chassis particularly configured to accept the newer blades. However, total rackmount component replacement of this sort is undesirable due to the overall system downtime and labor expense associated with such removal and reinstallation.
Accordingly, it is desirable to provide a rackmount chassis that can accommodate a range of blade widths.